Indices of Myocardial Oxygenation during Coronary-artery Revascularization in Man with Morphine Versus Halothane Anesthesia

Abstract

Adult male patients (12) undergoing coronary-artery revascularization are studied to compare the effects of a morphine vs. a halothane anesthetic technique on several indices of myocardial O2 supply and demand. Indices reflecting myocardial contractility, preload, afterload and heart rate were measured. Undesirable increases in systemic and pulmonary capillary wedge pressure were minimized using sodium nitroprusside as needed. After sternotomy but before revascularization patients anesthetized with morphine (mean 2.1 mg/kg) had significant (P < .05) increases in rate-pressure product, tension-time index, blood pressure, heart rate and relative myocardial ischemia, evidenced by significant ST-segment depression in the V5 lead of the ECG and a decreased diastolic pressure-time index/tension-time index compared with patients anesthetized with halothane (mean .75% inspired). Few difficulties associated with myocardial depression were seen in patients anesthetized with halothane. Halothane in a well-monitored environment is safe for use in patients without severe ventricular dysfunction undergoing coronary-artery revascularization.